Protein Immobilization on 3D-Printed Biomedical Resins for Biochip Applications

Three-dimensional-printed Biomedical resins are used in various medical applications, such as in the fabrication of medical devices. The work reported here considers stereolithography (SLA) 3D-printed surface-modified biomedical resin BioMED clear resin (Formslabs) as a biochip support material for the immobilization of proteins. The surface properties of 3D-printed Biochip (3DPBC) were modified by exposure to dielectric barrier discharge (DBD) plasma treatment and coating of an (3-aminopropyl)triethoxysilane (APTES) film. Bovine serum albumin (BSA) was immobilized onto the different surfaces to understand the nature of model protein interactions thereon. Water contact angle (WCA) for untreated 3DPBC was ~80°, which reduced by 30%–47% after the DBD plasma treatment at 49–198 W min m−2 plasma power. The decrease in WCA is primarily attributed to the inclusion of oxygen-related functionalities on the surface of 3DPBC. The addition of an APTES coating to the 3DPBC slightly increased the hydrophilicity of the surface by introducing nitrogen functionalities. BSA immobilization was observed on the as-prepared 3DPBC, the DBD plasma functionalized, and APTES coated 3DPBC, as highlighted by the increase in the intensity of N1s signals and presence of amide functionality through XPS measurements. This highlights that the protein (BSA) binding affinity to substrate surfaces increases from that with DBD treatment and then further to that with DBD treatment and APTES coating. The interactions between BSA and APTES coated surfaces are covalent, electrostatic, and hydrogen bonding. The results presented here provide a pathway for the preparation of novel renewable biochips based on 3D-printed biomedical resins.